Water Treatment ComponentsUnion ConnectorContact Us to PurchaseFeatures Suitable for use in RO drinking systems, purifiers, water treatment systems...etc. Specification Model Type Spec. Remark FI-0030 union connector 3/8 OD x 3/8 OD Made in Taiwan FI-0031 union connector 3/8 OD x 1/4 OD Made in Taiwan FI-0061 union connector 1/4 OD x 1/4 OD Made in Taiwan Application Prevents leaking. Match tubing to same diameter pipe fittings.